It will work. Yes, I would invest in a skimmer to keep the water to correct parameters. I have a reef octopus bh-1000(external pump), and the 1000 with the pump on the inside, they work great! If you get a third fish, make it something that will swim around more. The angler will just lay there. The fu Manchu will swim and perch. I'd say a Picasso(Huma) triggerfish. They swim only. Since you are upgrading in the future, you can just get them all juveniles now. I wouldn't go with a valentini, only because they are huge fin nippers. Maybe something else in the Toby family.